How should airways resistance be measured in young children: mask or mouthpiece?

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology

Background:

• Accurate airway resistance measurements are crucial for diagnosing and managing pediatric respiratory conditions.
• The interrupter technique (MicroRint) is a common method, but its application using different interfaces (mouthpiece vs. face mask) in young children requires evaluation.

Purpose of the Study:

• To compare the reproducibility and acceptability of airway resistance measurements obtained via the interrupter technique using a mouthpiece versus a face mask in children aged 4-7 years.

Main Methods:

• Fifty children performed Rint measurements using both a mouthpiece and a face mask with an integral mouthpiece.
• Reproducibility was assessed using intraclass correlation coefficients (ICC) and coefficients of variation.
• Acceptability was evaluated through participant preference.

Main Results:

• Both methods demonstrated comparable repeatability (ICC, coefficient of variation).
• Mean Rint values were significantly lower with the mouthpiece (0.81 kPa·L⁻¹·s) compared to the face mask (0.88 kPa·L⁻¹·s).
• Despite small mean differences, the methods were not interchangeable, as confirmed by ICC and limits of agreement.

Conclusions:

• Repeatable airway resistance measurements can be obtained from young children using either a mouthpiece or a face mask with the interrupter technique.
• Significant clinical and statistical differences exist between the two methods, precluding their interchangeable use.
• While children preferred the face mask, it was more time-consuming and did not yield more repeatable results.